An ice cool Charlize Theron kicks plenty of ass in this stylish Cold War action thriller from the co-director of John Wick, but the script leaves a lot to be desired.

Sporting a distractingly dodgy British accent and a Debbie Harry-style peroxide blonde hair-do, Theron plays MI6 agent Lorraine Broughton, who’s sent into Cold War Berlin to investigate the murder of a fellow agent (Sam Hargrave) and recover a missing list of undercover agents. Her contact in Berlin is shady MI6 station officer David Percival (James McAvoy), who seems to have gone a little too deep undercover as a contraband-toting wheeler-dealer and appears to have his own agenda.

Sure enough, Lorraine’s barely been in Berlin five minutes before she’s pursued by murderous KGB operatives under the direction of their ruthless boss (Roland Moller). Along the way she encounters a skittish would-be defector (Eddie Marsan) and seduces a French secret agent (Sofia Boutella).

Atomic Blonde is framed with a battered and bruised Lorraine recounting her Berlin adventures to her MI6 boss (Toby Jones) and the head of the CIA (John Goodman), which allows for sly editing gags, like cutting from a racy sex scene to Jones pouring himself a cup of tea and saying, “So you made contact with the French operative, and what then?” That’s not to say the film is full of laughs, however, as most other attempts at humour fall painfully flat.

Theron delivers an impressively physical performance that lays bear the physical cost of every punch – we first encounter her taking an ice bath, during which she slips a few of the bathtub ice cubes into a waiting glass of Stoli, that’s how damn cool she is. However, while she generates some steamy chemistry with Boutella, she’s a frustratingly cold presence for the majority of the film, which might be a desirable quality in a secret agent, but it makes her difficult to warm to as a character.

As for the supporting cast, McAvoy is a little too over-the-top (bellowing “I LOVE BERLIN!”, etc), which lends a weird awkwardness to his scenes with Theron, while Marsan emerges as the film’s most sympathetic character and he’s good value when required to produce a series of horrified reaction shots during a car chase, like he’s seriously reconsidering the whole defecting thing if this is what’s involved.

Given director David Leitch’s background as a stunt co-ordinator and fight co-ordinator, it’s not really a surprise to discover that the action sequences are the undisputed highlight here. There’s a terrific set-piece early on that involves a length of fire-hose, but that pales in comparison to the main event, a bravura ten minute sequence – during which Lorraine fights her way into a building, up some stairs, back down again and into a car chase – that appears to unfold in a single, uninterrupted take, thanks to some state-of-the-art digital trickery. It’s an exhilarating, jaw-dropping sequence that is enough of a reason to see the film in and of itself, but what really makes it work is the depiction of the physical cost involved, with the actors left gasping for breath and barely able to stand.

The other thing Atomic Blonde has going for it is its ultra-cool aesthetic, whether it’s the neon-drenched lighting, the depiction of Berlin at the exact moment that the Wall comes down, or Theron’s super-stylish wardrobe choices (also, this is the ’80s, so she’s allowed to look cool smoking). This is heightened by a fabulous ’80s synth pop soundtrack that a) is deployed in interesting ways, and b) will have you running to Spotify immediately afterwards.

The main problem with Atomic Blonde is the script, which seems to have taken a few liberties with the graphic novel its based on (The Coldest City by Antony Johnston and Sam Hart). Firstly, the plot is all over the place, failing to establish sufficiently high stakes for the mission and introducing confusing twists and turns that the audience simply doesn’t care about. And secondly, the dialogue is disappointingly dull throughout, making you wonder if the real reason that Theron’s character is so tight-lipped is that she read the script and decided she didn’t want to say any of it.

Ultimately, the combination of thrilling action sequences, a kick-ass soundtrack, the visual aesthetic and Theron’s sheer star power are just about enough to compensate for the film’s shortcomings elsewhere, but this is very much a case of style over substance.